Before 1500, truth about the natural world was was derived from ancient Greek or Roman sources. The Bible was also the accepted authority in Europe, and challenging it was dangerous.
By examining changes in the field of astronomy, we are able to understand how the scientific method came to challenge ancient and Biblical sources. The geocentric theory placed Earth at the center of the universe. This idea came from Aristotle and was expanded by Ptolemy. Christians embraced this view because they thought Earth was a special place made by God. In 1543, the publication of Nicolas Copernicus's findings disputed these long-held assumptions. Copernicus, a Polish cleric and astronomer, based his book on more than 25 years of careful observation of planetary movements. By 1610, Galileo, an Italian scientist, had confirmed Copernicus's theories by using a telescope. Galileo was put under house arrest by the Church, and his experience showed why challenging orthodox views was hazardous.
The scientific method came to be applied to all fields of study. It involved careful observation and thorough testing of ideas. Hypotheses are tested by experiments that produce data. Two 17th-century intellectuals, Francis Bacon and Rene Descartes, advanced what became known as the scientific method. The role of established religion in Western society was diminished, and secular thought became much more widespread.